[Milan HP]

After 3 years of experimenting, I have come to some conclusions related to artificial light for tomatoes:
1) The minimum light intensity at the tops of the plants to avoid legginess is about 3,000 lux. Of course, anything over that is better.
2) The optimal arrangement is if the light comes from all directions. That means commercial grow lighting panels are not ideal, as the light comes from above only.
3) Combining sorts of sources works better than just one type of source. Fluorescent tubes combined with LED bulbs and LED grow lights work well.
4) For each stage of the plant development you need different wave length combinations. At the beginning, LED or f. tube day light (6,500°K) is quite enough. Later, when they start developing flowers, adding LED red-blue grow light is very useful.
5) Luminescent tubes produce some UV light, so if they are used, the plants are less prone to sunscald when exposed to direct sunshine later. Not that they are resistant. Maybe some professional grow lighting panels produce it as well.


I haven't experimented with arc sources as they use too much power and produce too much heat. They might be the option for glasshouses, but I don't have one. If anybody is interested, I will publicize some photos of my lighting system. I am not rich, so I work with inexpensive equipment. The results are not bad.


Milan HP